Abstract [en]

This is the first study of adolescents suffering from anxiety disorder in Sweden to receive individually tailored internet-based treatment within a child and adolescent psychiatric clinic. The primary aim of this effectiveness study was to examine the effects of tailored internet-based cognitive behaviour therapy for adolescents.

11 adolescents, aged 15-19 years, were allocated to treatment after assessment. Screening consisted of online questionnaires followed by a diagnostic face-to-face interview at the clinic. Treatment consisted of individually prescribed cognitive behaviour therapy (CBT) text modules adapted for the age group. Therapist guidance was via an online platform along with telephone support and face-to-face sessions if needed.

Statistically significant improvements were found on all dependent measures immediately following treatment for the 8 adolescents who completed treatment. The within-group effect size on the Beck Anxiety Inventory, the primary outcome measure, was d = 2.51 at post-treatment and 80 percent (4/5) adolescents no longer met DSM-IV criteria for their primary anxiety disorder as measured by the Anxiety Disorders Interview Schedule for DSM- IV: Child and Parent Versions.

Based on the results from this pilot study the tentative conclusion might be that tailored internet delivered CBT could be useful for adolescents with anxiety disorders along with standard treatment delivered in child and adolescent psychiatric clinics.

Abstract [en]

Anxiety disorders share the feature of excessive fear, anxiety and related behavioural disturbances. Fear is defined as the emotional response to a real or a perceived imminent threat and anxiety is the anticipation of a future threat. The anxiety disorders covered in this thesis are panic disorder with or without agoraphobia, social phobia, post-traumatic stress disorder, generalized anxiety disorder and anxiety disorder not otherwise specified.

Cognitive behavioural treatment protocols are typically designed to target one specific disorder and falls under the definition of disorder-specific cognitive behavioural therapy. It is however unclear if this is the most optimal approach in regards to the high comorbidity between anxiety disorders and depressive disorders. Internet-based cognitive behavioural therapy has in the past generally been disorder-specific and from above mentioned predicament two alternative treatment approaches emerged, the tailored and the transdiagnostic approach that aims to simultaneously treat both principal and comorbid disorders. Previous trials on internet-based cognitive behavioural therapy have targeted adults in general and relatively few target adolescents, young adults and older adults.

The aims of this thesis were to further develop and test the effects of tailored internet-based cognitive behavioural therapy on the basis of age, for adolescents, young adults and older adults. Specifically by developing and testing the effects of individually tailored internet-based cognitive behavioural therapy for adolescents with anxiety and comorbid depressive symptoms and by adapting and testing the effects of individually tailored internet-based cognitive behavioural therapy for young adults and older adults with anxiety and comorbid depressive symptoms. These aims were tested in two pilot effectiveness studies (Paper I and III) and two efficacy randomised controlled trials (Paper II and IV). The results from these four trials showed significant results across all outcome measures with overall moderate to large effect sizes. The tentative conclusion based on these results is that tailoring internet-based cognitive behavioural therapy can be a feasible approach in the treatment of anxiety symptoms and comorbid depressive symptoms for adolescents, young adults and older adults. Despite the positive findings of the studies in this thesis, there is a need for more research examining the acceptability and effectiveness of internet-based cognitive behavioural therapy for adolescents, young adults and older adults with anxiety and depression before implementation on a larger scale.